I have read that the mitochondria of a zygote are all of maternal origin. Therefore, mitochondrial genes come from the mother. But, during fertilization the sperm has, in the middle piece, some mitochondria. Don't they get into the ovum and hence in the zygote? The tail piece of the sperm does not enter the ovum but I guess the middle piece does. I don't get this. Please help.

mitochondrial main origin is from the endosymbiotic theory. you should go through this first. From this theory it has been said that mitochondria used to be a separate living entity, but after being engulfed by a cell as endosymbionts.

Now according to your question of Mitochondrial inheritance, the mitochondria are mainly inherited from from their mother. The mitochondria present in the human or mammalian sperm usually get destroyed after fertilization. There is little amount of mitochondria present at the base of the Head of the sperm. This mitochondria is mainly generally required for the propelling of the sperm tail. Sometimes it has also been seen the destruction of sperm tail. Later with the genealogical DNA test it has been proved genetically that mitochondria evolved maternally to offspring, generally in case of mammals.

greatmicrobiologist wrote:mitochondrial main origin is from the endosymbiotic theory. you should go through this first. From this theory it has been said that mitochondria used to be a separate living entity, but after being engulfed by a cell as endosymbionts.

how is this related?

Adz: To my knowledge, the parental mitochondria are transferred but they are diluted many times with the mothernal ones, so they do not contribute significantly.